The present invention relates to disposable diapers provided with tape fasteners used when the diaper is put on a wearer""s body.
Conventional disposable diapers are provided with tape fasteners laterally extending from transversely opposite side edges of a rear waist region of the diaper so that the tape fasteners may be separably anchored on a front waist region of the diaper when the diaper is put on a wearer""s body. A specific example of such a tape fastener comprises a basic tape member which is elastically stretchable and contractile circumferentially of the diaper. An end of the basic tape member on a side of the diaper is joined to a corresponding side edge of the diaper and an end of the basic tape member remote from the diaper carries thereon a hook member as one component of mechanical fasteners. To put the diaper on the wearer""s body, the basic tape member is longitudinally stretched until said hook member can be engaged with a loop member attached to the front waist region :as the other component of the mechanical fastener. In general, the hook member is of a rectangular shape.
With such elastic tape fastener, its basic tape member and possibly the hook member carried thereon tend to be transversely curved away from the diaper as said tape fastener is stretched in a direction of waist-line in order to anchor the tape fastener to the front waist region. If the hook member also is curved together with the basic tape member, the hook member will be curved away from the surface of the loop member to be engage the hook member and make reliable engagement with the loop member difficult. In other words, an effective surface area of the hook member will become substantially smaller than its actual surface area. As a result, a desired high fastening effect can not be obtained even if the hook member of a relatively large size is employed.
In view of the problem as has been pointed out, it is an object of the present invention to utilize an available surface area of the hook member attached to the elastic tape fastener as efficiently as possible.
According to the invention, there is provided a disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the topsheet and the backsheet, longitudinally opposite ends extending in parallel to each other in a direction of waist-line and transversely opposite side edges extending in parallel to each other, a pair of tape fasteners extending outwards from the side edges, respectively, in the direction of waist-line, wherein: each of the tape fasteners has a basic tape member which is elastically stretchable/contractile in the direction of waist-line and a hook member; the basic tape member has a longitudinal direction extending in parallel to the direction of waist-line and a transverse direction being orthogonal to the direction of waist-line, the basic tape member including, in the longitudinal direction, a proximal end portion joined to one of the side edges of the diaper and a distal end portion opposed to the proximal end portion, and the hook member is attached to the basic tape member on an inner surface of the distal end portion so as to be spaced from the proximal end portion and has inner and outer side edges extending transversely of the basic tape member, and the inner side edge extends towards the proximal end portion in a transversely middle zone of the basic tape member.